We divide 865661 by 3
The aim is to understand the frequency of 3 in 865661.

Advancing to step 1:
3 goes into 8 2 times with a remainder of 2.
Write down 2 as next digit of the result. 
Result so far: 2.0
The remainder is 2 after subtracting 6 from 8.
Fetch the next digit (6) from the dividend, attach it to 2 and continue: 26 / 3

On to step 2:
If we divide 26 by 3, we get 8 and a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 28.0
If we subtract 24 from 26, we get 2.
Append the next digit (5) from the dividend to 2 and continue with: 25 / 3

On to step 3:
3 goes into 25 8 times with a remainder of 1.
Use 8 as the next digit of our solution. 
Result so far: 288.0
Deduct 24 from 25 and we're left with 1.
Grab the next digit (6) from the dividend, add it to 1, then carry on: 16 / 3

Moving on to step 4:
3 can be fit into 16 5 times, resulting in a remainder of 1.
Use 5 as the next digit of our solution. 
Result so far: 2885.0
If we take 15 away from 16, we end up with 1.
Bring next digit (6) of the dividend behind the 1 and repeat the process: 16 / 3

Step 5:
If we divide 16 by 3, we get 5 and a remainder of 1.
Write down 5 as next digit of the result. 
Result so far: 28855.0
The remainder is 1 after subtracting 15 from 16.
Take the next digit (1) from the dividend and append it to 1, then repeat: 11 / 3

Let's proceed to step 6:
If we divide 11 by 3, we get 3 and a remainder of 2.
The number 3 becomes the next digit in our result. 
Result so far: 288553.0
The remainder is 2 after subtracting 9 from 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
If we divide 20 by 3, we get 6 and a remainder of 2.
Use 6 as the next digit of our solution. 
Result so far: 288553.6
If we take 18 away from 20, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 8:
3 goes into 20 6 times with a remainder of 2.
Write down 6 as next digit of the result. 
Result so far: 288553.66
Deduct 18 from 20 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

After the division, we end up with 288553.66 and a remainder of 0.002.